package com.buka.util;

import cn.hutool.json.JSON;
import com.fasterxml.jackson.databind.ObjectMapper;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.security.MessageDigest;
import java.util.Random;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class CommonUtil {

    private static final Pattern EMAIL_PATTEN = Pattern.compile("^[a-zA-Z0-9_\\.]+@[a-zA-Z0-9\\._]+$");

    /**
     * 获取ip
     *
     * @param request
     * @return
     */
    public static String getIpAddr(HttpServletRequest request) {
        String ipAddress = null;
        try {
            ipAddress = request.getHeader("x-forwarded-for");
            if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
                ipAddress = request.getHeader("Proxy-Client-IP");
            }
            if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
                ipAddress = request.getHeader("WL-Proxy-Client-IP");
            }
            if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
                ipAddress = request.getRemoteAddr();
                if (ipAddress.equals("127.0.0.1")) {
                    // 根据网卡取本机配置的IP
                    InetAddress inet = null;
                    try {
                        inet = InetAddress.getLocalHost();
                    } catch (UnknownHostException e) {
                        e.printStackTrace();
                    }
                    ipAddress = inet.getHostAddress();
                }
            }
            // 对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
            if (ipAddress != null && ipAddress.length() > 15) {
                // "***.***.***.***".length()
                // = 15
                if (ipAddress.indexOf(",") > 0) {
                    ipAddress = ipAddress.substring(0, ipAddress.indexOf(","));
                }
            }
        } catch (Exception e) {
            ipAddress = "";
        }
        return ipAddress;
    }


    public static String MD5(String data) {
        try {
            java.security.MessageDigest md = MessageDigest.getInstance("MD5");
            byte[] array = md.digest(data.getBytes("UTF-8"));
            StringBuilder sb = new StringBuilder();
            for (byte item : array) {
                sb.append(Integer.toHexString((item & 0xFF) | 0x100).substring(1, 3));
            }

            return sb.toString().toUpperCase();
        } catch (Exception exception) {
        }
        return null;
    }

    //生成随机数   6位随机数  全是数组
    public static String getRandomCode(int length) {
        String source = "0123456789";
        StringBuilder sb = new StringBuilder();
        Random random = new Random();
        for (int i = 0; i < length; i++) {
            int i1 = random.nextInt(source.length());
            char c = source.charAt(i1);
            sb.append(c);
        }
        return sb.toString();
    }


    //生成复杂随机数  数字字母
    public static String getRandomString(int length) {
        String source = "0123456789qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM";
        StringBuilder sb = new StringBuilder();
        Random random = new Random();
        for (int i = 0; i < length; i++) {
            int i1 = random.nextInt(source.length());
            char c = source.charAt(i1);
            sb.append(c);
        }
        return sb.toString();
    }

    public static boolean checkMail(String mail) {
        Matcher matcher = EMAIL_PATTEN.matcher(mail);
        return matcher.matches();
    }

    public static void sendErrorMessage(HttpServletResponse response, Object obj) {
        ObjectMapper objectMapper = new ObjectMapper();
        //json  xml text html
        try {
            response.setContentType("application/json;charset=utf-8");
            response.getWriter().write(objectMapper.writeValueAsString(obj));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static String getDeviceInfo(HttpServletRequest request){
        String ipAddr = CommonUtil.getIpAddr(request);
        String ua = request.getHeader("User-Agent");
        String deviceInfo = CommonUtil.MD5(ipAddr + ua);
        return deviceInfo;
    }

}
